Pirs Whim The friend or foe cards from Battlebond are masterclasses in political multiplayer card design, Pir's Whim being the best
(You choose any number of permanents and/or players with counters on them, then give each another counter of a kind already there.) Better than any of the generic or limited counterspells you may already have in your stack
Heliod, Sun-Crowned puts a +1/+1 counter on target creature or enchantment you control whenever you gain life, and it can give another creature lifelink until the end of the turn through a two mana activated ability
When the spell resolves, and asks you to exile the card, you may use Rule 7s replacement effect to send it to the Command Zone
For example, a player may use a copy of Bushwhack printed in The Brother s War after its rotation out of Standard because it was also printed in Foundations
King Macar, the Gold-Cursed will be another great one to sneak through defenses since he removes a problem creature and gives you a pop of mana when he comes back right-side-up